diff options
Diffstat (limited to 'net/ipv4/netfilter/ip_conntrack_helper_h323.c')
| -rw-r--r-- | net/ipv4/netfilter/ip_conntrack_helper_h323.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/ip_conntrack_helper_h323.c b/net/ipv4/netfilter/ip_conntrack_helper_h323.c index 518f581d39ec..3052468a6ab1 100644 --- a/net/ipv4/netfilter/ip_conntrack_helper_h323.c +++ b/net/ipv4/netfilter/ip_conntrack_helper_h323.c @@ -22,6 +22,8 @@ #include <linux/netfilter_ipv4/ip_conntrack_tuple.h> #include <linux/netfilter_ipv4/ip_conntrack_h323.h> #include <linux/moduleparam.h> +#include <linux/ctype.h> +#include <linux/inet.h> #if 0 #define DEBUGP printk @@ -38,6 +40,13 @@ static int gkrouted_only = 1; module_param(gkrouted_only, int, 0600); MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper"); +static char *internal_net = NULL; +static u_int32_t internal_net_addr = 0; +static u_int32_t internal_net_mask = 0; +module_param(internal_net, charp, 0600); +MODULE_PARM_DESC(internal_net, "specify your internal network using format " + "address/mask. this is used by call forwarding support"); + /* Hooks for NAT */ int (*set_h245_addr_hook) (struct sk_buff ** pskb, unsigned char **data, int dataoff, @@ -77,6 +86,12 @@ int (*nat_h245_hook) (struct sk_buff ** pskb, unsigned char **data, int dataoff, TransportAddress * addr, u_int16_t port, struct ip_conntrack_expect * exp); +int (*nat_callforwarding_hook) (struct sk_buff ** pskb, + struct ip_conntrack * ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + TransportAddress * addr, u_int16_t port, + struct ip_conntrack_expect * exp); int (*nat_q931_hook) (struct sk_buff ** pskb, struct ip_conntrack * ct, enum ip_conntrack_info ctinfo, @@ -683,6 +698,76 @@ static int expect_h245(struct sk_buff **pskb, struct ip_conntrack *ct, return ret; } +/* Forwarding declaration */ +void ip_conntrack_q931_expect(struct ip_conntrack *new, + struct ip_conntrack_expect *this); + +/****************************************************************************/ +static int expect_callforwarding(struct sk_buff **pskb, + struct ip_conntrack *ct, + enum ip_conntrack_info ctinfo, + unsigned char **data, int dataoff, + TransportAddress * addr) +{ + int dir = CTINFO2DIR(ctinfo); + int ret = 0; + u_int32_t ip; + u_int16_t port; + struct ip_conntrack_expect *exp = NULL; + + /* Read alternativeAddress */ + if (!get_h225_addr(*data, addr, &ip, &port) || port == 0) + return 0; + + /* If the calling party is on the same side of the forward-to party, + * we don't need to track the second call */ + if (internal_net && + ((ip & internal_net_mask) == internal_net_addr) == + ((ct->tuplehash[!dir].tuple.src.ip & internal_net_mask) == + internal_net_addr)) { + DEBUGP("ip_ct_q931: Call Forwarding not tracked\n"); + return 0; + } + + /* Create expect for the second call leg */ + if ((exp = ip_conntrack_expect_alloc(ct)) == NULL) + return -1; + exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip; + exp->tuple.src.u.tcp.port = 0; + exp->tuple.dst.ip = ip; + exp->tuple.dst.u.tcp.port = htons(port); + exp->tuple.dst.protonum = IPPROTO_TCP; + exp->mask.src.ip = 0xFFFFFFFF; + exp->mask.src.u.tcp.port = 0; + exp->mask.dst.ip = 0xFFFFFFFF; + exp->mask.dst.u.tcp.port = 0xFFFF; + exp->mask.dst.protonum = 0xFF; + exp->flags = 0; + + if (ct->tuplehash[dir].tuple.src.ip != + ct->tuplehash[!dir].tuple.dst.ip && nat_callforwarding_hook) { + /* Need NAT */ + ret = nat_callforwarding_hook(pskb, ct, ctinfo, data, dataoff, + addr, port, exp); + } else { /* Conntrack only */ + exp->expectfn = ip_conntrack_q931_expect; + + if (ip_conntrack_expect_related(exp) == 0) { + DEBUGP("ip_ct_q931: expect Call Forwarding " + "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n", + NIPQUAD(exp->tuple.src.ip), + ntohs(exp->tuple.src.u.tcp.port), + NIPQUAD(exp->tuple.dst.ip), + ntohs(exp->tuple.dst.u.tcp.port)); + } else + ret = -1; + } + + ip_conntrack_expect_put(exp); + + return ret; +} + /****************************************************************************/ static int process_setup(struct sk_buff **pskb, struct ip_conntrack *ct, enum ip_conntrack_info ctinfo, @@ -878,6 +963,15 @@ static int process_facility(struct sk_buff **pskb, struct ip_conntrack *ct, DEBUGP("ip_ct_q931: Facility\n"); + if (facility->reason.choice == eFacilityReason_callForwarded) { + if (facility->options & eFacility_UUIE_alternativeAddress) + return expect_callforwarding(pskb, ct, ctinfo, data, + dataoff, + &facility-> + alternativeAddress); + return 0; + } + if (facility->options & eFacility_UUIE_h245Address) { ret = expect_h245(pskb, ct, ctinfo, data, dataoff, &facility->h245Address); @@ -1668,6 +1762,7 @@ static void fini(void) static int __init init(void) { int ret; + char *p; h323_buffer = kmalloc(65536, GFP_KERNEL); if (!h323_buffer) @@ -1678,6 +1773,22 @@ static int __init init(void) return ret; } + if (internal_net) { + if ((p = strchr(internal_net, '/'))) + *p++ = 0; + if (isdigit(internal_net[0])) { + internal_net_addr = in_aton(internal_net); + if (p && isdigit(p[0])) + internal_net_mask = in_aton(p); + else + internal_net_mask = 0xffffffff; + internal_net_addr &= internal_net_mask; + } + DEBUGP("ip_ct_h323: internal_net = %u.%u.%u.%u/%u.%u.%u.%u\n", + NIPQUAD(internal_net_addr), + NIPQUAD(internal_net_mask)); + } + DEBUGP("ip_ct_h323: init success\n"); return 0; } @@ -1696,6 +1807,7 @@ EXPORT_SYMBOL_GPL(set_ras_addr_hook); EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook); EXPORT_SYMBOL_GPL(nat_t120_hook); EXPORT_SYMBOL_GPL(nat_h245_hook); +EXPORT_SYMBOL_GPL(nat_callforwarding_hook); EXPORT_SYMBOL_GPL(nat_q931_hook); MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>"); |